Ford Pinpoint Test JF1-JF3: Ignition Coil Not Firing Diagnosis (DTC P0350-P0360)

This document is one page of a Ford pinpoint diagnostic test procedure (steps JF1 through JF3) for diagnosing an ignition coil that is not firing on an electronic ignition (EI) system controlled by the PCM. Step JF1 directs the technician to determine which coil is not firing using information from Pinpoint Test JB and a chart at the beginning of the pinpoint test, recording the cylinder, coil, and Test Pin numbers. Step JF2 offers an alternative method using Diagnostic Trouble Codes (DTCs) to identify the non-firing coil. Both steps carry a NOTE that electronic ignition timing is entirely controlled by the PCM, is NOT adjustable, and that attempting to check base timing will produce false readings. Step JF3 checks the functionality of the coil circuit: DTCs P0350 through P0360 indicate ignition coil 1 through 10 primary circuit faults, with possible causes including an open or short in the Ign Start/Run circuit, an open or grounded CD circuit in the harness, a damaged coil, or a damaged PCM. The test involves disconnecting the coil, connecting an incandescent test lamp across the coil harness connector pins, disabling the fuel pump via the inertia fuel shutoff switch, and cranking the engine. A consistently blinking lamp means the coil circuit is OK (go to JF4); no blink indicates a coil circuit fault (go to JF5).